Improvement in screw-clamp supports for rock-drill spindles



` GEORGE-ALLEN. ,Y Improvement in Screw-Clamp Supports kfor R0ck-Dri|| Spindles. NO. 128,092. I Pajtentgd June 18, 1872.

Y Witnesses: t Inventor .I l 655577K@ .dttorneg/s.

UNITED STATES PATENT OFFICE.

GEORGE ALLEN, OE WATERFOBD, NEW YORK.

IMPROVEMENT IN SCREW-CLAMP SUPPORTS FOR ROCK-DRILL SPINDLES.

Specification forming part of Letters Patent No. 128,092, dated J une 18, 1872; antedated June 12, 1872.

To all whom it may concern:

Beit known that I,GEORGE ALLEN, of Waterford, in the county of Saratoga and in the State of New York, have invented certain new and useful Improvements in Mining-Tools; and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing and to the letters of reference marked thereon making a part of this specification.

The nature of my invention consists inthe construction of the box, through which the screw of a coal-drill passes, in two pieces, hinged together at one side and fastened by a screw at the other, so that the box may be tightened as it wears from use. In order to enable others skilled in the art to which my invention appertains to make and use the same, I will now proceed to describe its construction and operation, referring to the annexed drawing, in which- Figure 1 is a front view, and Fig. 2 a side view of the box. v

A and B represent the two halves of the bo through which the coal-drill screw O passes. These parts A B are provided on one side with ears a c for the passage of a rod or bolt, b, whereby they are hinged together.' Through the other side of the part A passes a screw, D 5

or said screw may be cast in with that part of the box. This screw passes through a groove in the corresponding sid'e'of the part B, and a thumb-nut, E, beingplaced on the end of said screw and screwed down, tightens the box. The two parts of the box are provided with f female screw-threads corresponding with the threads on the screw O.

By means of the screw D and thumb-nut E the box can be tightened as it gets worn by use, thereby always keeping a good worm in the box till it is worn down to the face, and then it will last as long as a new box of the kind now generally in use.

Having thus fully described my invention, what I claim 'as new, and desire to secure by Letters Iatent, is-

The within-described ,bisected box A B, hinged on one side, as described, and conne-cted on the other side by a screw, D, and thumbnut E, substantially as and for the purposes set forth.

ln testimony that I claim the foregoing I have hereunto set my hand this 17th day of November, 1871.

GEORGE ALLEN. Witnesses: e Y

J. CRAMER, 2d, H. T. STrLEs. 

